import java.util.TreeSet;

public class Teste2 {

	private static TreeSet<GPair> set;
	
	public static void main(String[] args) {

		set = new TreeSet<GPair>();
		set.add(new GPair());
		set.add(new GPair("a"));
		set.add(new GPair("a", "A"));
		
		System.out.println(set);
		System.out.println("".isEmpty());
	}

}
